Sulphur dioxide is a typical by-product of industrial processes such as the smelting of sulphide ores or burning of sulphur containing fuels. If vented to the atmosphere without treatment, it can cause environmental problems such as acid rain.
The treatment of sulphur dioxide by thermal reduction to sulphur using methane, or a gas containing predominantly methane, such as natural gas, is known. However, in practice, such thermal reduction processes suffer from either soot formation or the need to add steam to the reaction mixture to avoid soot formation. In both scenarios, particularly the second, fuel consumption is high.
Furthermore, known implementations of the process have relatively low sulphur recovery efficiency, typically up to 95% based on sulphur dioxide in the feed compared with sulphur produced.
A way to ameliorate these problems has been sought.